We have a lot of structured data at Latacora: most of which off of APIs and appliances. You often want to build regression tests against it, but the real data is sensitive. We built this tool to redact the data so that the exact IPs, security groups, et cetera are replaced, but their replacements have the same shape (e.g. IPs to IPs, MAC addresses to MAC addresses, random hex strings to random hex strings of the same length...) and that the _same_ IP occurring more than once gets mapped to the _same_ replacement IP. This is useful because e.g. I might care that two instances are in the same security group, and that doesn't work if I just blindly randomize each one separately.
It's extensible, but right now that involves editing code. If you can express it as a regex, you should be good to go. (I'd like to make it configurable via config file, but not enough people have asked so far.)